The CMA Algorithm Study In The Smart Antenna

In the current wave environment of increasingly complex, the anti-interference issue in a variety of applications has become increasingly important, to reduce interference as a means of the damage, Adaptive Array was a widespread and in-depth research topic, Adaptive Array also known as smart antennas, it is one of the important technologies in the next three or four generation in the field of mobile communication, there are two types of algorithms in the smart antennas: Blind algorithms and non-Blind algorithm, CMA is an important algorithm in the blind algorithm, it can fast restrain, and easy to implement, computational complexity is low, one of the hot issues as the field of signal processing, the CMA in the 1990s, has been extensive and in-depthy researched, but it is mainly has been used in the blind equalization. Then people have been proposed the many improvements for the blind algorithms, and it has been applicated to multi-user detection, blind signal separation, interference suppression and the beam-forming, in varying degrees, resolved these problems in some areas.In this paper, the smart antenna structure and working principles are firstly introduced, then detailed CMA domestic and international development condition, the working principle and application, the Blind Channel balanced constant modulus algorithm, multi-level CMA, adjusting the weighted value of the multi-level CMA, adding initialization forecast and adjusting the weighted value of the multi-level constant modulus algorithm, use Matlab language to simulate,study algorithm on the advantages and disadvantages, use the smallest squares error criteria and the largest SNR criteria of the best filtering criteria to analy, for analying the adding initialization forecast and adjusting the weighted value of the multi-level constant modulus algorithm has the best performance in the anti-interference and reduces the power of extracting signal.